UPDATE 1-Tennis-Nadal to team-up with Sampras for Mumbai in new league

(Adds details)

MUMBAI, March 2 (Reuters) - World number one Rafa Nadal will team up with 14-times major champion Pete Sampras for Mumbai in the inaugural International Premier Tennis League (IPTL) later this year, tournament organisers said on Sunday.

Serena Williams, the top-ranked women's player, will headline the Singapore team alongside Tomas Berdych and Andre Agassi in the off-season tournament from Nov.28 to Dec.14, which is styled on cricket's franchise-based Indian Premier League.

Four teams - Bangkok and Dubai being the others - will compete in men's and women's singles, men's and mixed doubles and a men's legends singles with one set per match, and no advantage scoring.

Serb Novak Djokovic and former women's number one Caroline Wozniacki will lead Dubai while Britain's Andy Murray, Frenchman Jo Wilfried-Tsonga and Victoria Azarenka of Belarus were picked by Bangkok when the teams were drafted on Sunday in Dubai.

The 2014 season will feature 24 matches across the four host cities with all four teams competing in a round-robin format in each of the four cities, organisers said.

"As an Indian and the owner of the tournament I'm delighted that the world number one Rafa Nadal is playing for an Indian city," promoter Mahesh Bhupathi said on Sunday.

"I think the teams are evenly balanced, I'm happy for the players who have been picked."

The IPTL has been generally well-received by the world's top players although not all have signed up.

Roger Federer, winner of a record 17 grand slam titles, and former women's world No.1 Maria Sharapova will not be appearing.

"I don't know that much about it to be honest," Federer said in Dubai this week where he won the title.

"I wish I could tell you exactly what's going on. I just didn't sign up because I didn't want to. I just first wanted to see it get off the ground."

Some will question why players who have regularly raised concerns about the length of the season are willing to take long-haul flights to play matches in the short off-season.

It promises to be extremely lucrative, however, with organisers saying Sunday's initial draft had seen an outlay of $24 million with salaries for each team expected to be between $4 and $10 million.

"Really happy that I was drafted for Dubai...Thanks," Serbia's Janko Tipsarevic said on Twitter while his compatriot Ana Ivanovic said she was happy to join Nadal playing for Mumbai.

"So excited to learn I have been picked for #Mumbai team for #IPTL! Can't wait to get on court and get together with my great teammates! :))" she said. (Reporting by Sudipto Ganguly, additional reporting by Martyn Herman in London; editing by Steve Tongue and Pritha Sarkar)